Macintosh Plus Chirping Noise

[bibilit]

Will  be hard to figured out, if The Plus is still making the ticking sound, as Techknight said before, the regulation side is not working properly and nothing will work (no screen, no chime...)

Problem is, can be a lot of things (capacitors, but those are reliable, diodes, transistors) anything preventing the power supply from working properly.

 

[MacintoshMan1999]

Hey, I'm back. Sorry for the absence, I should have said I was taking a break.

Anyway, I've started to work on the Mac Plus again. I tried to upload a photo but the website does not want to cooperate with me right now. The picture is of a pair of tubes/light bulbs on the analog board. I'd also like to ask how to check the flyback transformer safely.

Thanks!

 

[MacintoshMan1999]

Would you trust this flyback?

https://www.ebay.com/itm/Flyback-Transformer-Line-Output-Apple-MAC-Replacement-6174Z1003G-HR-46176/323042869316?epid=12014096612&hash=item4b36db0044:g:j5MAAOSwExlacW4o

 

[MOS8_030]

I recently purchased a flyback from this seller. Good item.

https://www.ebay.com/itm/157-026C-Flyback-1570026B-Replaces-Apple-HR-42031/400922654856

 

[MacintoshMan1999]

Cool, thanks 

 

[MacintoshMan1999]

Could the flyback be the cause of the Mac regulation problem? I've been hearing that's a common problem.

Thanks, Jack

 

[MacintoshMan1999]

I've found a culprit!

 

[MacintoshMan1999]

I don't think the Flyback is suppose to look like that!

 

[mjhagen]

The yellow stuff is normal, are you referring to that?

 

[MacintoshMan1999]

Really? Yes, I was because all of the new flybacks I've seen don't have that on them... Also, the reason I thought that it was a culprit was because it looks like it flowed down towards the bottom of the Mac at some point. I'm not an expert so please excuse my ignorance. Thanks for pointing that out!

-Jack

 

[MacintoshMan1999]

The screwdriver is pointed at the bottom of the mac.

 

[Juror22]

Please take one good high-res shot of the outside of the analog board and another hi-res shot of the inside of the computer, showing as much as you can of the CRT, cables, etc.  So far, most of the small items that you have focused on have turned out to be alright, so it might be helpful to look over everything, including the current symptoms (if you could list them) and work our way to a diagnoses.

Oh, and be super careful not to touch anything while its plugged in or running.

 

[MacintoshMan1999]

Alright, I'll do that.

 

[MacintoshMan1999]

Back of analog board:

 

[MacintoshMan1999]

Inside W/ CRT:

 

[MacintoshMan1999]

Symptoms:

1: When together CRT makes a static-like noise. (like when a CRT is turned off but constant)

2: The Transformer behind the magnet with the "5A" on it (is it the low voltage?) makes a chirping type noise when distant, but when close can also hear a ticking sound as well.

3: Speaker makes "fup" noise only when the logic and analog board are together

4: There is no startup chime or an image on the screen.

5: When I got the Mac Plus the startup chime would sound but no picture would be on the screen, I however eventually read if I tap the left side swiftly and a image shows up that some of the solder joints were broken/damaged  and just needed soldered again.

6: The internal and external drives would make a horrible grinding noise constantly because both had a broken eject motor gear.

7: Unfortunately I was a bit of an idiot and had the Mac on with the external floppy drive connected and OPENED UP out the back "checking it out" (I didn't know about the gear yet), then the Mac shat out and went into its current state. Smoooooooth move on my part...... :-/

I'm guessing ether my stupidity did it, or the Mac really just shat out on its own.

Soooooo... yeah these are the symptoms

Thanks for the help!

-Jack

 

[mjhagen]

The only obvious thing I see is the solder joints on J4 (?), they seem to be cracked. Have you read chapters 5 and 6 of Macintosh Repair & Upgrade Secrets? I think those might be helpful here.

Looking at it some more, maybe a lot more solder joints could use a touch up, the flyback included.

 

[techknight]

Check the secondary rectifier diodes for shorts. 

 

[MacintoshMan1999]

Check the secondary rectifier diodes for shorts. 

Alright, I'll do that

The only obvious thing I see is the solder joints on J4 (?), they seem to be cracked. Have you read chapters 5 and 6 of Macintosh Repair & Upgrade Secrets? I think those might be helpful here.

Looking at it some more, maybe a lot more solder joints could use a touch up, the flyback included.

I'll take a look and touch the solder joints up. And I don't think I've read any of the Macintosh Repair & Upgrade Secrets book, I'm looking at it now...

 

[MacintoshMan1999]

I Checked the current coming out of the anode cap, no current whatsoever. I'm going to order a new flyback.

Probably from here: https://www.ebay.com/itm/157-026C-Flyback-1570026B-Replaces-Apple-HR-42031/400922654856?hash=item5d58da3888:g:xs4AAMXQgwNSJyrC:sc:USPSPriority!78620!US!-1

-Jack